He was succeeded by his son, the second Earl. In 1741, on the death of his cousin Hugh Primrose, 3rd Viscount Primrose, he succeeded as fifth Baronet, of Carrington (see the Viscount of Primrose, which title became extinct on the death of the third Viscount, for earlier history of the baronetcy). His son, the third Earl, sat in the House of Lords as a Scottish Representative Peer from 1768 to 1784. He was succeeded by his son, the fourth Earl. He represented Helston and Cashel in the House of Commons and served as Lord Lieutenant of Linlithgowshire. In 1828 he was created Baron Rosebery, of Rosebery in the County of Edinburgh, in the Peerage of the United Kingdom, which gave him and his descendants an automatic seat in the House of Lords.
His grandson, the fifth Earl (the son of Archibald Primrose, Lord Dalmeny), was a prominent Liberal politician. He served as Foreign Secretary in 1886 and between 1892 and 1894 and as Prime Minister of the United Kingdom between 1894 and 1895. In 1911 he was honoured when he was created Baron Epsom, of Hyde in the County of Surrey, Viscount Mentmore, of Mentmore in the County of Buckingham, and Earl of Midlothian, in the Peerage of the United Kingdom. Lord Rosebery was married to Hannah de Rothschild, the wealthy daughter and heiress of Baron Mayer Amschel de Rothschild, through which marriage the Mentmore Towers estate in Buckinghamshire came into the Primrose family.
Their eldest son, the sixth Earl, represented Midlothian in Parliament from 1906 to 1910 but then did not take an active part in politics until the 1940's, when he served in Winston Churchill's 1945 caretaker government as Secretary of State for Scotland. He was also Chairman of the National Liberal Party from 1945 to 1947. As of 2007 the titles are held by his son, the seventh Earl, who succeeded in 1974.
The Heir Apparent to the earldom is usually styled Lord Dalmeny, but the current Earl, while heir apparent to his father, the sixth Earl, was styled Lord Primrose instead, to avoid using the same courtesy title as his elder half-brother, Archbald Ronald Primrose, who had been styled Lord Dalmeny before his death in 1931. The current heir has returned to the usual practice and is styled Lord Dalmeny.
The Heir Apparent's Heir Apparent is his son the Hon. Albert Caspian Harry Primrose (b. 2005)